1. Field of the Invention
The present invention relates to a cleaning apparatus and method and a computer readable medium, for performing a cleaning process on a substrate, such as a semiconductor wafer.
2. Description of the Related Art
In the process of manufacturing semiconductor devices or flat panel display devices (FPD), liquid processes are frequently used, in which a process liquid is supplied onto a target substrate, such as a semiconductor wafer or glass substrate. For example, processes of this kind encompass a cleaning process for removing particles and/or contaminants deposited on a substrate.
As a liquid processing apparatus used for this purpose, the following apparatus of the single-substrate processing type is known. Specifically, a substrate, such as a semiconductor wafer, is held in a rotatable state, and a process liquid is supplied onto the front surface, back surface, or front and back surfaces of the wafer, while the wafer is rotated. Consequently, a liquid film is formed on the front surface, back surface, or front and back surfaces of the wafer, thereby performing a process.
As a apparatus for performing a cleaning process while forming a liquid film on the back surface or front and back surfaces of a substrate, the following apparatus is known (for example, Jpn. Pat. Appln. KOKAI Publication No. 9-298181). Specifically, a rotatable rotary plate is disposed below the back surface of the substrate. The rotary plate has an opening at the center, which is provided with a non-rotatable liquid delivery plate having a substrate support function and a liquid delivery port. The liquid delivery plate is movable up and down such that the liquid delivery plate receives the substrate in a state projected upward and then is moved down to place the substrate in a horizontal state on holding accessories provided on the rotary plate. A cleaning liquid or rinsing liquid is supplied from a liquid delivery nozzle, which extends downward from the liquid delivery port, into a gap between the substrate and rotary plate to form a liquid film. In this state, cleaning is performed on the back surface of the substrate.
The liquid delivery plate surrounding the liquid delivery port may be contaminated with a chemical solution scattered thereon during a process. Further, the liquid delivery plate may be contaminated when an unprocessed substrate carrying contaminants comes into contact therewith. If a portion around the liquid delivery port is contaminated, this contaminated portion may touch and contaminate the back surface of the substrate after cleaning, when the substrate is supported by the liquid delivery plate for unloading. Accordingly, it is preferable to clean the liquid delivery plate when the substrate is processed. However, the liquid delivery port is non-rotatable in general, and the liquid delivery plate around the liquid delivery port is also non-rotatable. Hence, a liquid film cannot be sufficiently formed on the liquid delivery plate during a cleaning process or rinsing process, resulting in insufficient cleaning.